7) 
The inner branch of the uropods reaches considerably beyond 
the telson, and is fringed with plumose sete. The considerably 
longer outer ramus is similarly fringed on the inner margin 
and round the apex as far as the tooth which occurs low down 
on the outer margin. 
The integument of this species is not strongly calcified, 
but it has the property of retaining for years in preservative 
media (spirit and formalin) the fascinating blue colour to which 
the specific name refers. This attains especial intensity on the 
eye-stalks, on the scales of the second antennae and on the uro- 
pods. The latter, when expanded with all their feathered sete on 
either side of the telson, may bear comparison with a beau- 
tiful butterfly. On the first, third and sixth segments of the 
pleon there are transverse bands of deep blue, these being 
distal in the first and third segments, median in the sixth. 
There is also often a deepening of the colour along the medio- 
dorsal line of all the segments, producing an illusory appearance 
of a continuous carina. 
The specimen figured at full length measured 95 mm. On 
dissection the tips of the rostrum and telson proved to be 
broken, so that when perfect the specimen was probably 
100 mm. long. The specimen from which the enlarged separate 
carapace was drawn, measured 75mm. The largest specimen 
received was over five inches in length, with a carapace of 
over two inches. 
Locality —From Nahoon River (tidal for several miles. 
inland) on E. coast near East London. 
This lovely species appears to be very nearly related to 
P. monodon, but separated by smaller size and feebler calcifi- 
cation, the constancy of the rostral dentation, the absence 
of an exopod from the fifth pair of legs, and the unique colouring. 
In regard to the latter character it is proper to notice that 
there is a certain amount of variability, so that Dr. Gilchrist 
wrote of some of the specimens as being almost white. But 
even in these extremely pale examples the points of blue 
are very numerous. Mr. John Wood, of East London, when 
obligingly sending a second supply of specimens to Dr. Gilchrist, 
wrote in reply to an enquiry on the subject, “ As regards the 
blue colour, this may have become more pronounced since 
these prawns first left my hands, but I remember noticing it 
distinctly at the time they were taken out of the Nahoon 
River. I may mention these prawns I am sending you are 
believed to be absent from our rivers during the winter months.” 
